Problem: Ben is $30$ years old and Daniel is $2$ years old. How many years will it take until Ben is only $3$ times as old as Daniel?
We can use the given information to write down an equation about how many years it will take. Let $y$ be the number of years that it will take. In $y$ years, Ben will be $30 + y$ years old and Daniel will be $2 + y$ years old. At that time, Ben will be 3 times as old as Daniel. Writing this information as an equation, we get: $30 + y = 3 (2 + y)$ Simplifying the right side of this equation, we get: $30 + y = 6 + 3 y$. Solving for $y$, we get: $2 y = 24$. $y = 12$.